How to fix warped faces when using boolean modifier on curved objects?
First, unless you have good reason to keep it high-poly, I would simplify with a CtrlE &gt; Un-Subdivide:

Then boolean it, give it some corrections like dissolve or merge some vertices, when you're good on a side or on the front, use Symmetrize:

Create a bevel on the joint:

It looks good. If you want a higher poly, subdivide.